Safety switch mechanism



April 22 1924.

1,491,278 L. SIEBERT SAFETY SWITCH MECHANISM Filed Oct. 17. 1921 Inverzior.

L. Siebefi.

35 i switch constructimis as at present man-u- Patented Apr.- 22, 1924.

UNITED STATES" PATENT OFFICE.

LESTER SIEBER'I, OF SAN FRANCISCO, CALIFORNIA, 'ASSIGNOR TO DRENDELL ELEC- TBICAL & vMANUZEAC'NIIRING CO., INC.,

PORTION OF CALIFORNIA 'Application filed October 17, 1921. Serial No. 508,405.

To all it may concern: Be it known that I, LESTER SIEBERT, a citizen of the United States, residing at the city and county of San Francisco and State of Calif rnia, have invented certain new and usefu Improvements in Safety Switch Mechanism, of which the following is a specification. v

The present invention relates to a safety switch mechanism for precluding accidental contact with the switch lever or fuse terminals during such time as the switch is in closed position, and for precluding accidental contact with the stationary or live contact jaw when the switch is disenga ed.

therefrom, and. the invention relates to t at t pe of apparatus illustrated in my condiiig application Serial No. 298,116, filed Among the advantages of the present invention are the provision of a means controlled by the opening and closing of the switch lever for protecting the live contact jaw on the disengagement of the switch therefrom; the provision of means whereby a shield or protector for the fuse and fuse terminalsis held in locked position by the position of the switch lever, and is released at such time as the lever is moved to open position; to provide means whereby the protector for the live jaw contact is capable of being locked trhereover precluding the closi115 ofithe switdh lever.

he present invention has numerous advantages .from a point of safety over lever featured, in that item precludes the chang. ing of a fuse an inexperienced person, during such time as the switch is in closed position. It also precludes accidental. contact with the lever when the same is in closed position, and prevents access being had to the stationary contact jaw when the same is engaged by the lever. invention precludes the accidental contact with thestationary contact jaw by the automatically movin thereovzr of a protector designed to concea the same when the lever is disengaged therefrom. 1

With the above mentioned and other objech! in vievi, the invention consists in the novel c and combination of parts hereinafter described, illumted in the accompanying drawings, and set forth in the.

SAFETY SWITCH MECHANISM.

May

being the live contact at all times.

01: SAN FRANCISCO, CALIFORNIA, A COE- reference is directed to the accompanying drawings, wherein- Figure 1 is a view in side elevation of the preferred embodiment of my invention, with the fuse shield and switch lever or blade in closed position, the latter locking the former from being opened;

Figure 2 is a view in broken top planof the invention illustrated in Figure 1.

Figure 3- is a view similar to Fi ure 1 HEISSUED with the switch in 0 en position'an illustrating the fuse shie d raised exposing the fuse, also the jaw protector in a posltion overlying the stationary contact jaw, and

Figure 4 is a detail sectional view of the operating spring and the hinge joint for the jaw protector.

In the drawings, wherein like characters of reference designate corresponding parts throughout the several views, 1 indicates a base or support, which carries on its surface a conventional stationary contact jaw 2, the lever or blade fulcrum support 3 and the fuse terminals 4, said parts 3 and 4 being' illustrated as connected beneath the base by a conductor 5', and the fuse terminals being 'connected'by a suitable fuse 6.- A blade or switch lever 7 is ivotally mounted, as at 8, on the upper e118 of the part 3 and is adapted for swinging movement to engage the contact jay 2, which is illustrated as In the resent illustration, a three blade switch is Illustrated, but it is apparentthat the invention is equally adapted for use in connection with 'one blade switches, and to simplify the description of the present invention, the following specification is Written in the singuhr, as it willbe readily understood that a switch containing any number of blades me be employed. liingedas at 9 to the base 1 immediately in advance of the stationary contact jaw 2 is a. suitable jaw protector provided with the rear Wall 10., top wall 11 and end walls 12, but one of which is illustrated in the drawing. The front of ,said protector is open to receive the contact aw 2, and said protector is adapted to be swung upwardly by the tension of a spring 13 in the hinge part 9 thereof. Preferably at each end,'sa d jaw protector carries idler rollers 1st, and with the same are adapted to contact the lower terminal side edges 15 of a blade shield 16. The shield 16 is provided with a top wall 17 and downwardly extending side walls 18, which are adapted to ride on the members 14 when the lever is moved to approximately, closed position. The shield 16 encloses the blade or lever 7 and the same is secured thereto to pivot therewith, and when the lever is in closed position engaging the jaw 2, the lower edges of the side walls of the shield extend approximately into contacting relation with the surfaceof the base 1, and protect the blade or lever and jaw 2 from accidental contact. A handie 19 affords a means for operating the lever 7 extending upwardly from the base 1, at one end of the protector 10 is a blade 20 formed with a locking aperture 21, and which is adapted to register with an apertured plate 22 on the end of theprotector 10, when said protector is in a position of alignment with the jaw 2, said blades 20 and 22 with their aligned ports affording a means for locking the protector concealing said' jaw 2 and preventing the closing of the blade or switch 7.

Fulcrumed on an axis 21 parallel to the fulcrum point 8 of the blade or lever 7 is a fuse shield 22 substantially U-shaped in cross section and of a. length adapted when overlying said terminals l. and enclosing the fuse 6 therein, to be disposed with its free end in slight spaced relation with the rear of the blade shield 16. Like the shield 16, the side walls of the shield 22' extend in close proximity to the surface of the base 1 when the shield 22 is in closed position overlying contacts 4, as in Figure 1, preeluding accidental contact with said contacts 4, as above explained.

The shield 22' is provided with an operating handle or finger piece 23 to facilitate the operation thereof, and forwardly from op posite sides thereof extend the spring fingers 21, the same adjacent their outer ends being outwardly bowed or bent as at 25, as clearly illustrated in Figure 2 of the drawings. The side walls 18 of the blade shield 16, at a point offset from alignment with the blade fulcrum 8, are provided with the outwardly projecting locking pins 26 havingbeveled outer ends 27. The spring fingers 24 are adapted, on the downward movement of the shield 22, to enclose the terminals 4: and fuse 6 to ride over the beveled faces of the pins 26, and pass beneath said pins whereby the shield 22 is locked in its closed position during such time as the blade or lever T is in engagement with the jaw 2. On thedisengagement of the blade or lever 7 from the jaw 2, a movement is imparted to the pins 20 about the blade or lever fulcrum 8, moving said pins in alignment with the outwardly bent or curved portions 25 of the. fingers 2'1 permitting the raising of the fuse shell, at which time access can be had for replacing or renewing the fuse 6.

Closure springs 28 are provided on each side of the fuse shield 22' to insure the movement of the same to closed position on pressure being released from the handle 23; these springs insuring the closing of the shield 22 to conceal thecontacts l and fuse 6 immediately on the operator releasing his griIp on the handle 23.

7 my present construction it will be observed that, so long as the blade or lever 7 is in engagement with the stationary contact jaw 2, access for the renewal or replacement of the fuse 6 is precluded due to the locking of the fuse shield 22 in closed position, but that said shield will be readily raised on the disengagement of the blade or lever 7 from the stationary jaw 2. It will also be apparent that, immediately on the. disengagement of the blade or lever 7 from the contact jaw 2, the protector 10 is automatically moved by the spring 13 in a. position to overlie and conceal the contact jaw 2, which in the present case is the live terminal at all times, and this prevents acci dental contact therewith. It will also be observed that the movement of the blade or lever 7 to closed position causes the forward portions of the lower edges 15 of the side walls 18 thereof to engage the members 1 1 at opposite ends of the protector and pivoting said protector on its fulcrum 9 to expose the said jaw 2 for engagement by the blade or lever 7.

I claim 1. A safety switch mechanism including a. base, a stationary contact jaw carried thereby, a pivotally mounted switch lever carried by the base and movable into and out of engagement with said jaw; a shield carried by the lever for protecting the same against accidental contact, a jaw protector hingedly mounted on the base adjacent to said jaw to'swing to and from said jaw; a spring for moving said protector to overlie said jaw on the disengagement of the lever therefrom, and apart associated with the jaw protector and adapted for engagement on the movement of said lever to closed position, whereby a movement is imparted to said protector to pivot the same to expose said jaw and permit the engagement of said lever therewith.

2. In combination with a pivotally mounted switch, a pair of fuse terminals adjacent thereto and in circuit therewith, a pivotally mounted shield for overlying said termi nals to preclude accidental contact with the Same, a SPIiDg'fOr normally maintaining said shield in a position to overlie said terminals, and means for lockin said shield in closed position, said means a' apted for releasing on the movement of said switch to break the circuit controlled thereby.

3. In combination with a pivotally mounted switch, a pair of fuse terminals adjacent thereto and in circuit therewith, a shield mounted to pivot on an axis parallel with sociated with the switch; a spring finger associated with one of said shields;-and a locking part associated with the other for engagement by said finger for lockingthe first mentioned shield in closed position during such time as the switch is in closed position.

5. In combination with a lever switch and its associated contacts; a pair offuse terminals adjacent thereto and in contact there-.

with; a pivotally mounted shield normally overlyingsaid terminals; a shield associated with the switch; a spring finger carried by the fuse shield; a locking part associated with the switch shield for engagement by the spring finger to lock said fuse shield in closed position, said part adapted for movement on the opening of said switch to permit-the clearance thereof by said spring finger, enabling the opening of the fuse shield when said switchis in open position.

6. In combination with la pivoted lever switch and its jaw contact; a pair of fuse terminals adjacent to said switch; a movable shield normally overlying said terminals; a shield enclosing said switch and movable therewith; a movable protector associated with said jaw contact and adapted for enclosing the same on the opening of said switch; and means for locking said terminal shield in closed position when said switch is closed, said means adapted for releasing on the opening of said switch.

7.. In combination with a pivoted. lever switch; a jaw contact with which the same engages; a shield enclosing the lever switch and movable therewith; and a movable protector carried by the base and adapted for movement to overlie said jaw contact, and a part carried thereby and adapted for engagement on the closing of said lever for removing said protector to expose said jaw contact. y

. In testimony. whereof I have signed my name to this specification.

LESTER SIE'BE'RT. 

